Known slide-in fan modules generally have axial flow fans with vertically oriented fan axes and upper air exit sides. The slide-in fan modules are provided with a cover, which in the vicinity of air exit faces has circular openings.
As a result of a relatively large hub area, in the centre of the axial flow fan and in regions between and outside the air exit faces, so-called "dead areas" arise, in which there is no or only a limited air flow. These "dead areas" have a particularly disadvantageous effect in means or systems, where the slide-in fan modules, in order to save installation space, are positioned at a very limited distance from a reception space with the equipments, subassemblies, components or other objects to be cooled or ventilated. Hot spots can then be formed, which give rise to problems or even to the failure of an equipment, subassembly, etc.
EP 470 926 A1 discloses a ventilation means for consoles equipped with printed circuit boards, in which at least one cooling air-sucking in blower is provided spaced from a reception space for parallel circuit boards. On the lower guide elements engages an air distribution plate, which is placed in the grid of guide elements for the minimum circuit board openings for the blower cooling air flow. Between the blower outlet or an upper edge of a fan slide-in module and the air distribution plate, a storage capacity is formed on the underside of the guide elements where, as a result of the minimum openings and baffles located therein, a pressure is formed, which is intended to lead to a uniform, directed flow. As a result of the height of the storage capacity, which roughly corresponds to that of the fan, an equalizing section is defined. A disadvantage associated therewith is the reduction of the installation space of a cabinet, frame or casing, which is contrary to the constantly increasing demand for an optimum utilization of the installation space.
DE 34 17 451 C2 discloses a slide-in casing constructed for EMC shielding and ventilation from two-shell plates. Each shell is provided with vent openings, which have a slot-like construction and in the case of two adjacent shells are not aligned with one another, which leads to a wave-like flow of the air passing through. The casing is made from plastic and is provided on the inside and/or outside with an electrically conductive coating.
An electrical device with thermally highly loaded electrical components of plate-like carriers described in DE-OS 1 908 825 has cooling lines between the components, which are fixed to the carrier plates in such a way that their slot-like exit openings are directed onto the components.
U.S. Pat. No. 4,214,706 discloses a cooling system for equipment cabinets and circuit boards and subassemblies arranged therein, which has a ventilation chamber with a rectangular cross-section. The outer walls of the ventilation chamber, which are directed towards the circuit boards and electrical sub-assemblies, have elongated openings. To obtain a uniform pressure in the ventilation chamber connected with a frontally positioned blower, a partition with round holes is provided, so that two partial chambers are formed.